The present invention relates to an apparatus for introducing measured or dosed quantities of pulverized or pulverulent materials into a carrier gas stream. This invention also relates to the application of the aforementioned apparatus to a tank for the distribution of pulverized materials.
An apparatus for proportioning and extracting pulverized materials from a distribution tank of the type herein discussed, has been disclosed in Luxembourg patent application No. 84-462 corresponding to U.S. patent application Ser. No. 550,565, assigned to the assignee hereof, all the contents of which are incorporated herein by reference. The invention described in the pending U.S. patent application Ser. No. 550,565 is particularly applicable to the operation of injecting solid fuels into a shaft furnace during a metal refining process. In this particular field of application, one dosing device is provided for each tuyere stock, or at the most, for each pair of tuyere stocks, such that a whole set of dosing devices are required for the distribution and intermediates storage tanks used to store the pulverized materials. As a consequence and particularly, for maintenance purposes, in order to dismantle a dosing device, it is necessary either to provide a shut-off valve between each dosing device in the tank or alternatively, to shut down the tank and each of the dosing devices. This time consuming and expensive shutdown must be performed each time maintenance work is to be carried out on a particular device or tank.